


Fulfilling A Fantasy

by SpyroForLife



Category: Gravity Falls
Genre: Anal Fingering, Anal Sex, BillDip, BillDipFord, Billford - Freeform, Biting, Blow Jobs, DipFord - Freeform, Incest, M/M, NSFW, One Shot, Smut, Spitroasting, Threesome - M/M/M, incestuous kissing
Language: English
Status: Completed
Published: 2016-03-08
Updated: 2016-03-08
Packaged: 2018-05-25 15:14:07
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,043
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6199993
Author URL: https://archiveofourown.org/users/SpyroForLife/pseuds/SpyroForLife
Summary: <blockquote class="userstuff">
              <p>Bill has been in a relationship with Dipper for a year, and tonight Dipper offers to do any fantasy Bill wants. Even if it's really weird, he'll do it for him. Bill admits to wanting a threesome. With Ford. Oh.</p>
            </blockquote>





	Fulfilling A Fantasy

**Author's Note:**

> I spent so much time wondering if I could that I didn't stop to think whether or not I should.

“Hey, Bill?” Dipper murmured into his partner’s ear.

“Yeah?” Bill replied quietly, hips stilling for a moment. He was currently perched on the human’s lap, both stripped down to their underwear and close to taking those off too, and both were anticipating. The past several minutes has been slow grinding and making out, and Bill just couldn’t get enough of touching the other. But he was willing to stop and listen, curious as to what they would do next.

“We’ve been together for a year,” Dipper said. “Well… it’s been exactly a year since we kissed for the first time, since we first had sex.”

“Has it? Wow, time sure flies.” Bill slid his hands up through Dipper’s hair. “I’ve learned a lot since then. Thanks for giving me a second chance. I appreciate everything you and the rest of your family have done for me.”

“Heh…” Dipper kissed his neck. “You’re welcome. So, since we’ve been together this long, and you’ve been doing so well… Tonight you deserve something special. Why don’t you tell me about your fantasies? Whatever you’ve wanted that we haven’t done before, I’ll do it. Or even if it’s something we’ve done but you really like. Tonight is for you.”

“My fantasies?” Bill considered it. He had quite a number of fantasies, as he had a very active imagination and several kinks, but Dipper has pretty much gone through all of them with him by now. “I don’t know, we’ve done a lot of stuff together already…” He did have very dark thoughts that sometimes popped up, but he satisfied those through more intense play. He was lucky his partner was a masochist. And then the really sadistic ideas, the demonic urges to actually and truly hurt the other… those he pushed into the far corner of his mind and ignored.

Bill shrugged a shoulder. “I can’t really think of anything.”

“Oh come on, I’m sure you have an idea,” Dipper encouraged. “Something really weird that you figured I wouldn’t like, or at least something we enjoy but haven’t done in a while, I’m sure you can think of something.” He bounced the other a little on his leg, arms around his waist.

“Well…” Bill hesitated as one fantasy occurred to him. It was a more recent one, and he’s never brought it up because he knew humans considered that sort of thing immoral, but Dipper was pretty open-minded, so maybe it was worth bringing up. “There is one I’ve thought about, but it’s… really messed up.”

“What is it? I won’t make fun of you.”

“I know you won’t, but it’s kinda disturbing.”

“That’s fine, now you’ve got me curious.” Dipper held him closer, and his eyes were so curious, Bill couldn’t say no to him.

“Mm, fine, I sometimes fantasize about both you and Ford fucking me,” Bill said in a rush.

Dipper blinked, then slowly furrowed his brow. “What?”

“I uh… I’ve thought about both you and Stanford. Taking me at the same time. I…” Bill’s cheeks grew hot at the way Dipper was looking at him, and he turned his face away. “I told you it was messed up. You probably think that’s really gross. I’m sorry.”

Dipper was aware of Bill’s trysts with his great uncle and was okay with it, he just tried not to think about it. But for Bill to admit to him that he had such a fantasy… It definitely had him curious. “No, it’s fine, you have unorthodox kinks and I’m fine with that. You like sleeping with both of us, it’s only natural for you to imagine what it’d be like at the same time. I’m sure our relation is the last thing on your mind. Fantasies are like that.” Dipper nibbled Bill’s neck, making him squirm, and he sighed at the feeling of the other’s erection rubbing into his. “It’s okay.”

“But you’d never actually do it,” Bill said. “It’d have to remain a fantasy. Humans think incest is wrong.”

“Well hold on now.” Dipper leaned back as he considered it. “It’s not like Ford and I would be having sex with each other. We wouldn’t even need to touch each other, necessarily. We can both just focus entirely on you. If he’s okay with it, then we could possibly do that.”

“Really?” Bill stared at him. “You wouldn’t be grossed out having your great uncle in here with us, naked, doing sexual things to me? And knowing he’s seeing you in the same way?”

“Well geeze it’s weird when you call attention to it like that. But I really think we could. If it’ll make you happy. Hold on.” Dipper gently set him down on the bed, pulled a robe on, and left the room.

His mind was reeling as he went downstairs. Bill wanted to have a threesome with him and his uncle. Just thinking about that squicked him out, he and Ford were related, though if one really wanted to get down to genetics it was only by at most 12.5% (he had seen a chart in one of his classes and checked out of curiosity). But still. It was more about the morality of the thing.

Then again, he told himself, they were both adults. They could consent to each other. It may be weird, but they knew each other well, and there was trust between them. And again, it wasn’t like he was going to have sex with Ford. _That_ was definitely out of the question. He was just going to share Bill with him. He was thinking too much, wasn’t he?

“Hey, Ford,” Dipper called, leaning into the living room. Everyone was in there, more than aware of what was happening upstairs, though Bill was gracious enough to put up a silencing spell that prevented sound from leaving their room.

“Dipper, I thought you were with Bill,” Ford replied, but he got up to come see what he needed.

Dipper pulled him aside and said quietly, “Okay this is really weird but please keep an open mind. I told Bill that I’d do whatever he wanted tonight, and asked him about his fantasies and… he kinda admitted to wanting a threesome.”

“Of course he would, demons aren’t above that sort of thing, they do it all the time,” Ford said flippantly.

“Heh, yeah, well… he kinda specified who he wanted the third person to be. He… wants to have both of us at once.”

Ford stared, then reached into his pocket and began opening a bottle of pills. “Okay I think I need to go to bed.”

“He really seemed to want to do it,” Dipper said. “I said I’d ask but I totally get it if you don’t want to, it is pretty wrong and he just doesn’t get that.”

Ford slowly recapped the bottle. “I’m sure he doesn’t, but what you’re asking is… I mean I do like sleeping with him, I know how much he likes me, but for us both to have sex with him, it’s just… I don’t think I’d be comfortable with that, you’re barely grown up and we’re related…”

“Only by like 12.5%,” Dipper pointed out.

“True, but… do you _really_ want to do that?”

Dipper shrugged. “I want to do something special with Bill. I’d be okay with it if you were.”

“Are you really saying you would have sex with him with me in the room? With me touching him too or doing whatever he wants? That’s really something you’d want to participate in? Does it not seem incredibly awkward?”

“I know it would be but I just…” Dipper gestured helplessly, then sighed. “I was willing to try and forget about my own morals just to make Bill happy. He’s done things for me that he didn’t like much, I figured I would return the favor. I’ll tell him you don’t want to do it. Sorry for bothering you.” He started up the stairs.

“Wait.” Ford took a step after him, paused, and then said, “I can try it. Just this once, just for him. But I’m not going to touch you at all if I can help it.”

“Sounds good to me. Thank you.” Dipper gratefully nodded to him, then hurried back upstairs.

Bill was sitting cross-legged on the bed where he had been left, lost in thought, but he perked up when Dipper entered. “Well?”

“He’s going to give it a try,” Dipper said, putting the robe aside and climbing up with him. “He’s really weirded out by the idea but he said he’ll do it for you.”

Bill grinned. “This is going to be so fun! I can’t wait.”

Ford joined them after a few moments, nervously messing with his hair before meeting Bill’s eyes. “You do know how wrong humans think incest is, right?”

“Sure but you aren’t going to be having sex with Pine Tree, you don’t have to kiss him or anything. I just want you both to have your way with me. One at one end, one at the other.”

Ford blushed. “Ah. Well, um…” He glanced at Dipper. “As long as you’re okay with this…”

“I am if you are.”

“All right…” Ford tugged his sweater off, and Bill watched with rapt attention. He cast Dipper an excited look.

“This is really happening, this is gonna be fun!” he said with a grin.

“Heh, I hope you enjoy it. And I’m gonna try not to think about the fact that I’m about to find out what my great uncle is like in bed.”

“I can’t say I’m particularly stoked to find out what you’re like either,” Ford shot back.

“Boys, boys, you’re both wonderful,” Bill assured them. “I love you both, that’s why I’ve been wanting to do this. If it’s so great with each of you, I can only imagine how great it’ll be with both.”

Dipper nuzzled him. “I know. Which is why I’m just not going to think about it. I’m just gonna enjoy whatever happens.”

Bill looked over as Ford dropped the last of his clothes, coming over in just his boxers and climbing up next to them. “All right, thank you both for having an open mind about this, I really appreciate it. I didn’t think this fantasy would ever happen, but here we are!”

“Just tell us what to do,” Ford said.

“Right. Okay, well… usually I imagine that you’ve both captured me, you’re holding me down and using me for your pleasure.” Bill’s cheeks quickly grew flushed as he described it. “You’re rough with me, pushing me around, giving me orders, and it’s really exciting. Ford, I want you to have me on my knees as you take me from behind, and Dipper, I want you to make me suck you off.”

Dipper inhaled. It did sound pretty hot, having Bill at his mercy like that, and he could almost pretend Ford wasn’t related to him. He nodded and met Ford’s eyes.

“Sounds like a plan,” Ford said. He gripped Bill around the waist, pulling him away from Dipper and kissing him deeply. Bill moaned as he responded, and Dipper’s underwear grew tight. He quickly fumbled for their lube.

“How much more foreplay do you need?” Dipper asked.

“I don’t need much,” Bill mumbled, leaning back from Ford, who instead began kissing his throat and chest. “I’m pretty turned on from earlier, j-just… Nngh, Ford, you can loosen me or just go for it, your choice.”

Ford took the bottle and opened it, laying Bill down on his stomach. “Stay down.”

Bill shivered. “Okay.”

Dipper got in front of the demon, slipping his underwear off and dropping them. Bill propped himself up on his elbows, eyeing his erection.

“Well go on, treat me,” Dipper said.

“Of course.” Bill licked up the hot flesh, swirling his tongue around the tip and making Dipper moan, before taking the head into his mouth.

“God, Bill,” Dipper exhaled, closing his eyes and gripping Bill’s hair in a hand. This was good. He was going to keep his eyes shut.

Ford, meanwhile, continued his preparation. He poured some lube onto a finger and worked it into Bill with no warning, making the demon grunt and wiggle. He tried to pull back to make more noise, but Dipper tightened his grip.

Ford chuckled at the frustrated noise Bill made, pumping his finger in and out, occasionally teasing the other’s prostate. Dipper let Bill lean back enough to catch his breath, and heard him whimper.

“He’s really hard,” Ford said, and Dipper opened an eye to glance at his uncle. He found he was slowly ceasing to care about the other being here, as hormones began pumping and desire took over. Ford seemed to be more at ease too. One of his hands was under Bill’s belly. “He’s dripping.”

Dipper moaned, cock twitching. He slid himself back into Bill’s mouth, and the other shuddered as he took it.

Ford slid his finger out of Bill and applied a coating of lube to his length. Dipper hadn't even realized that he had finished undressing. “Ready, Cipher?”

Bill steadied himself with his legs, lifting a hand to give a thumbs up.

“Good.” Ford thrust into him with no further comment, and Bill’s back arched, a desperate noise escaping him next time he bobbed his head back.

“Fuck, Bill,” Dipper groaned, guiding the other’s pace. He could feel Bill’s body being moved forward and back, Ford’s thrusts pushing Bill harder onto Dipper, and soon they had their movements synced.

Ford gripped Bill’s hips tightly with both hands, no longer touching his arousal, wanting him to feel utterly dominated. That was clearly what the demon wanted.

Dipper kept a hand wound into Bill’s hair, and the other hand rested over one of Bill’s as a small reassurance. And if things got to be too much, Bill would signal him with a slap. But Bill was enjoying himself, not struggling at all.

Ford leaned down over the demon, one hand sliding up further, fingers tracing the lines of his muscles. He thrust in harder, rocking Bill with his strong movements, and kissed along the back of Bill’s neck. Dipper could feel the man’s hair brush against his knuckles, and opened his eyes a bit. Ford looked focused, his eyes closed, sweat rolling down his skin. His tongue dragged around the side of Bill’s neck, and then he bit down over the demon’s jugular.

The dangerous thrill made Bill cry out, and Dipper felt a pulse of pleasure go through his body. Okay, this was hot. This was _really_ hot.

“None of that, keep going,” he ordered him, pulling him back down.

Bill looked up at him, pupils blown with lust. He smirked next time he leaned back, and Dipper heard his voice in his mind.

_I knew you’d be into it._

Dipper scoffed, seizing Bill’s hair with both hands and thrusting, needing more friction. Bill didn’t even choke, taking it like a champ. He kept his jaw relaxed, eyes squeezing shut as Dipper fucked his throat.

The younger human was moaning loudly, legs growing numb from the pleasure, balls tightening, he was so close…

And Ford was just as close, his thrusts short and hard, sheathing himself completely into Bill each time he went in, breath escaping in husky pants. Bill’s muscles were shaking, but he still kept on, pressing himself back onto Ford even as he pleasured Dipper.

As Dipper’s pleasure reached its peak, he got a sudden urge, and he moved before his common sense could stop him. He leaned forward and seized Ford’s cheeks, lifting his chin and pressing their lips together.

Ford grunted, eyes widening with shock, and Dipper almost immediately broke away, body shaking as he came. He felt Bill swallow and pull his mouth away, but Dipper just stared at Ford.

“I-I… I’m sorry, I wasn’t thinking, I just…” he tried to apologize, but Ford interrupted him.

“That never happened.”

Guilty, Dipper nodded in understanding. Then he let out a muffled shout when Ford seized his neck and dragged him forward, kissing him harshly, their teeth knocking together before the older man suckled on one of his lips.

Dipper twitched, a spasm of pleasure going through him despite how his stomach coiled with unease. He dropped his hands to Bill’s shoulders, using them for support.

Ford groaned and pulled away, burying inside Bill with a final hard thrust before coming. Dipper fell back, catching himself on his elbows, eyes wide as he stared at Ford. His eyes darted toward Bill as the demon moaned, hips jutting forward as he finished onto the bedspread.

“Coming untouched, huh?” Ford growled to him, pulling out. He gave Bill’s ass a slap. “Slut.”

“Takes one to know one,” Bill said tiredly, lazily vanishing the liquid before collapsing down onto Dipper’s lap, sighing loudly.

Ford made an indignant noise and sat back on his heels, catching his breath. Realizing Dipper was still staring at him, he turned red and said, “That second kiss didn’t happen either.”

“Why did you do that?” Dipper asked in confusion.

“I don’t know. Why did you kiss me?”

“...I don’t know.”

“Exactly.” Ford touched his lips, hesitated, then wiped them off. Dipper did the same. “We’re a couple of fucked up Pines. No wonder Bill likes us so much.”

“The fucked up ones are the best,” Bill slurred, face quite comfortably buried into Dipper’s stomach.

“Did you have fun?” Dipper asked him.

“Yeah, I loved it. Thank you. I know how weird that must have been for you both, so thanks for doing it anyway. I really had fun.”

Dipper stroked the other’s hair, and Ford got up and began dressing. They didn’t speak to each other until Ford said goodbye and headed out, arms stiff at his sides. Dipper returned it, and it wasn’t much longer before they heard the shower start.

“Mm,” Bill hummed as he and Dipper slid under the covers. “Maybe you and him should have sex.”

“Bill!”

“I’m just joking. But man, hormones make you do some crazy stuff, huh? Heh, I’m exhausted, I’m going to bed. Goodnight, love.”

“Goodnight.” As Dipper sank into his dreams, he knew he would have lots to think about.


End file.
